Phosphoric esters

ABSTRACT

New and valuable substituted O,O-dialkylthionophosphoric esters having a good insecticidal action and a process for controlling insects with these compounds.

United States Patent m1 Dietsche et al.

[ 1 Feb. 27, 1973 PHOSPHORIC ESTERS Filed: Sept. 25, 1970 Appl. No.: 75,704

US. Cl ..260/308 C, 260/468 C, 260/471 C,

- 260/482 C, 424/200, 424/269 Int. Cl. ..A0ln 9/36, C07f 9/16 Field of Search ..260/308 C [56] References Cited UNITED STATES PATENTS 3,594,390 7/1971 Timmler et al ..260/308 Primary ExaminerAlton D. Rollins Attorney-Johnston, Root, OKeeffe, Keil, Thompson & Shurtleff [57] ABSTRACT New and valuable substituted 0,0-dialkylthionophosphoric esters having a good insecticidal action and a process for controlling insects with these compounds.

5 Claims, No Drawings PHOSPHORIC ESTERS The present invention relates to new and valuable 0,0-dialkylthionophosphoric esters and insecticides containing these compounds.

It is known from Belgian Patent No. 609,209 to use dithiophosphoric esters as insecticides; however, their action is not satisfactory.

We have now found that 0,0-dialkylthionophosphoric esters having the formula where R and R are identical or different and each denotes a lower alkyl radical (methyl, ethyl),

R denotes hydrogen or lower alkyl (methyl, ethyl, n-

propyl, isopropyl, isobutyl, sec-butyl), cycloalkyl (cyclohexyl), aryl (phenyl) or substituted aryl (omand p-) chlorophenyl, m-CF -phenyl, m-nitro, p-nitro, 2,4-dinitro, p-tolyl, p-bromophenyl, 2,4,6- trichlorophenyl) and R denotes lower alkyl (methyl, ethyl, n-propyl,

isopropyl, isobutyl, sec-butyl), lower alkenyl (allyl), lower alkoxyalkyl (3-methoxypropyl, 3 ethoxylpropyl, Z-methoxylethyl, 2-ethoxyethyl), lower alkyl-thioalkyl B-methylthiopropyl, 3- ethylthiopropyl), haloalkyl (y-chloropropyl, chloroethyl, monochloro-tert-butyl, lchloromethylpropyl-l, B-chloro-n-propyl), lower alkoxycarbonylethyl (a-carbalkoxymethyl, a-carbomethoxymethyl, a-carbethoxymethyl, a-carbon-propoxymethyl, a-carboisopropoxymethyl, amethyl-a-carbalkoxymethyl), aryl (phenyl) or substituted aryl,

have a good insecticidal action.

The new active ingredients may be prepared by reacting 0,0-dialkylthionophosphoric ester halides having the form ula where R has the above meanings and Hal denotes a halogen atom, with urazoles having the formula where R and R have the above meanings.

The urazoles may be prepared in conventional manner (v. C.A.55, 22298 h, Arch. Pharm. 299 (1) 43- 45 [1966]) as follows:

1 R -N=c=0 R4NNH 11m bar, in H II base (CHsONfl) R4NN 0:0 (i7-ONa 011,011 canon I t= III The corresponding hydrazocarboxylic ester, to which isocyanate is added on and which is subsequently cyclized with a suitable base, is thus obtained from the hydrazine component with diethyl carbonate.

The substituted R of the hydrazine component denotes lower alkyl or cyclohexyl, aryl or substituted aryl, and R in the isocyanate denotes lower alkyl (methyl, ethyl, n-propyl, isopropyl, n-butyl, secbutyl, tert-butyl), lower alkoxyalkyl, lower alkylmercaptoalkyl, haloalkyl, lower alkoxycarbonylethyl, cycloalkyl (cyclohexyl), aryl or substituted aryl. Suitable aryl substituents are: l to 3 halogen atoms (chlorine or bromine), trifluoromethyl, methylsulfonyl, lower alkyl and lower alkoxyl. The aromatic may be substituted by several different groups selected from those listed.

The active ingredients are preferably produced in the presence of acid binding agents; suitable agents are alkali metal carbonates, alkali metal alcoholates, alkali metal hydroxides and organic bases. Another preferred method consists in reacting the alkali metal salts of the urazoles mentioned above with thionophosphoric ester chlorides of the above formula. The reaction is advantageously carried out in an inert organic solvent at a moderate (30 to C) temperature. Ketones, benzene, dioxane, toluene, nitriles such as acetonitrile, propionitrile, dimethylformamide and esters of organic acids have proved to be particularly suitable as solvent. The yield may be increased by heating and stirring the mixture for a fairly long time at the recommended temperature after the starting materials have been mixed. The thionophosphoric ester chlorides used as starting materials are known in the art. Owing to the large number of suitable isocyanates and hydrazines, many differently substituted urazoles may be obtained whose phosphoric esters have excellent insecticidal properties.

The new thionophosphoric esters are usually colorless to yellow oils which are insoluble in water and are difficult to distil, even at a substantial subatmospheric pressure, without any decomposition occuring. They have an excellent action on a plurality of insect pests (aphids, mosquits larvae, caterpillars, houseflies), and some of them have a low toxicity on warm bloods. Because of their excellent insecticidal properties the active ingredients are most suitable as pesticides in the plant protection field.

The production of the compounds is illustrates below with reference to examples:

The urazoles described in the literature are predominantly those having aromatic substituents'. Cyclization in accordance with equation (III) is therefore usually carried out in aqueous systems with caustic soda solution, followed by the precipitation with acids of the water-insoluble urazole. This method for isolation cannot, however, be used with urazoles bearing only aliphatic substituents, as these urazoles dissolve very readily in water.

The process for cyclizing type 11 compounds has therefore been modified. The sodium salts of the type III urazoles may be obtained directly in pure form by slowly adding a methanolic solution of the stoichiometric amount of technical grade sodium methylate or 50 percent aqueous caustic soda solution to a boiling solution of II in 98 percent ethanol. After a short reaction time, the urazole salt 111 is precipitated upon cooling, either directly or after benzene has been added. Where no spontaneous crystallization of the salts occurs, the solution may be concentrated or evaporated to dryness since the reaction proceeds almost quantitatively. The urazole salts obtained by this procedure are usually sufficiently pure for subsequent phosphorylation. Preparation of the sodium salt of 2-methyl-4-allyl-1,2,4 -triazolidine-dione-3,5

59 parts by weight of ethyl methylhydrazinecarboxylate is dissolved in 150 parts of benzene; 0.5 part of triethylamine is added and 45.7 parts of allyl isocyanate in 50 parts of benzene is dripped in. The reaction proceeds exothermically and, to complete the reaction, the mixture is stirred for a further hour at 60 C. After removal of the benzene, the oily residue is taken up in 150 parts of ethanol and 85 parts of 32 percent by weight methanolic sodium methylate solution is dripped in. The whole is subsequently stirred for an hour at 60 C, after which the solvent is removed. The powdered product is completely freed from solvent by treatment in a rotary evaporator for an hour at 60 C. Yield: 95 percent of the theory, m.p. 235248 C.

Calc.: C: 40.7; H: 4.52; N: 23.7

Found: C: 41.1; H: 5.0; N: 22.9

The invention is illustrated by way of the following examples.

EXAMPLE 1 Preparation of 0,0-diethy1-0-[ 1 ,4-dimethyl-1,2,4- triazo1on-( 5 )-yl-(3 )]-thionophosphate S ll (l)P 2E101 22.6 parts by weight of the sodium salt of 1,4-dimethy1- l,2,4-triazolidinedione-3,5 is suspended in 150 parts of acetonitrile. While stirring thoroughly, 284 parts of diethylthionophosphoryl chloride is added at 50 C over a period of 5 to minutes. The mixture is then boiled under reflux for 5 hours. The end of the reaction is easily detectable by the change from the initial coarse suspension to a very finely divided suspension of precipitated sodium chloride. Without previous separation of the sodium chloride (extremely difficult to filter off as a result of the fine dispersion), the reaction mixture is evaporated at 60 C in a rotary evaporator using a water jet vacuum and the oily residue is taken up in 300 parts of benzene. The solution is washed once with 50 parts of saturated aqueous sodium hydrogen carbonate solution and twice with 50 parts each time of 3 percent aqueous sodium hydrogen carbonate solution, after which the solution is dried over anhydrous sodium sulfate. After evaporation in a rotary evaporator under a water jet vacuum and devolatilization for 2 hours under an oil pump vacuum (approx. 0.5 mm) at C, there remains 30 parts (71.3 percent yield) of a pale yellow oil having a refractive index u 1.4905. Analysis (in Calc.: C: 34.2;H: 5.7; P: 11.0): S: 11.4

Found: C; 34.0;H: 5.9; P: 10.6; S: 11.6 LD 50 mg/kg of rat EXAMPLE 2 Preparation of 0,0-dimethyl-0-[ l,4-dimethyl-1,2,4- triazolon-( 5 )-yl-( 3 ]-thionophosphate 22.6 parts of the sodium salt of 1,4-dimethyl-1,2,4- triazolidinedione-3,5 is suspended in 150 parts of anhydrous benzene. After an addition of 0.26 part of finely powdered CuCl -21-l,O, 24.1 parts of dimethylthionophosphoryl chloride is added at 50C over a period of 10 minutes and while stirring thoroughly. The whole is then stirred for 4 hours at 50 C and subsequently boiled for 6 hours under reflux. The reaction mixture is worked up as described in Example 1. After de-volatilization for 2 hours under an oil pump vacuum (0.5 mm) at 90 C, there remains 14.5 parts (a yield of 38.2 percent) of a pale yellow oil having a refractive index u 1.5060. Analysis (in Calc.: C: 28.4;H: 4.7;N: 16.6; P: 12.2;S: 12.7

Found:C:28.4;l-l:4.9;N: 17.0; P: 11.5;S: 12.5

EXAMPLE 3 Preparation of 0,0-diethyl-0-[4-phenyl-1,2,4-triazolon- (5 )-yl-( 3 )l-thionophosphate A G V...

35.4 parts of 4-pheny1-l,2,4-triazolidinedione-3,5 is suspended in 150 parts of methanol. While stirring and cooling with ice, 35.4 parts of sodium methylate (32 percent in methanol) dissolved in ml of methanol is dripped in; a clear solution is formed. After evaporation in a rotary evaporator there remains a crystalline mass of the monosodium salt of 4-phenyl-l,2,4-

triazolidinedione-3,S which is suspended in 200 parts of aeetonitrile. While stirring thoroughly, 37.8 parts of diethylthionophosphoryl chloride is dripped in at room temperature and the whole then boiled under reflux for 5 hours. The reaction mixture is worked up as described in Example 1. There is obtained 42 parts of a turbid oil from which crystals separate out after standing for 3 days. After diluting with 25 ml of benzene, suction filtering and washing twice with benzene, 14.7 parts (a yield of 22.3 percent) of a crystalline substance having a melting point of 110 to 111 C is obtained. Analysis reveals the substance obtained to be the desired phosphorylation product. Analysis Calc.: C: 43.8; H: 4.9; N: 12.8; P: 9.4; S: 9.7

Found: C: 44.1; H: 5.0;N: 12.9; P: 9.6; S: 9.8

The compounds listed below may be prepared analogously; in all cases the substances are fairly thin oils which even under a high vacuum cannot be distilled without decomposition occurring.

Compounds having the general formula:

NNR 1 i P-O O N RLO No. 11 ,14 R R 11,, 1 -c,11, ca, 11 1.4971 2 -c,11,, cu, c1-1 1.4905 :1 cm, c.11, cn, 1.4858 4 cm, (2,11, cu, 1.4150 5 (EH; C l-1 CH, 1.4841 cm, c.11, c1 1, 1.4838 7 cm. sec-C,H. cu, 1.4803 8 -C,H tertCJ-I, CH, 1.4849 9 4: 1-1 -CH;-CH=CH; CH, 1.491 1 10 -C1H|1 H C". 1.4973

11 -c,11, Q cu, 1.5291

1s -c,11, cu ,c,11, 1.4802 14 -c cm. p.11, 1.4755 15 -c,11, p.11, .c,11, 1.4720 16 -c,11, 12.11. 0,11, 1.4750 17 cm, -CH,-CO0-C,H, cu, 1.4842 1s 01-1, cu, cn, 1.5060 19 c1-1, 0,11, CH, 1.4944 20 c,11. 4:11,-c11,c1 cu, 1.4970

Cl 21 c.11. -C1110g e11, 1.494s

m.p.56-57C n L54l1 m.p.59-60C m.p.82-83C The insecticides according to the invention may be used as solutions, emulsions, suspensions or dusts. The form of application depends entirely on the purpose for which the agents are being used; in any case it should ensure a fine distribution of the active ingredient.

For the preparation of solutions to be sprayed direct, hydrocarbons such as tetrahydronaphthalene, and alkylated anphthalenes may be used as spray liquids.

Aqueous formulations may be prepared from emulsion concentrates, pastes or wettable powders by adding water. To prepare emulsions the ingredients as such or dissolved in a solvent may be homogenized in water or organic solvents by means of wetting or dispersing agents. Concentrates which are suitable for dilution with-water may be prepared from active ingredient, emulsifying or dispersing agent and possibly solvent.

Dusts may be prepared by mixing or grinding the active ingredients with a solid carrier.

The following examples demonstrate the excellent insecticidal action of the new active ingredients.

For comparison purposes, the compound described in Belgian Patent No. 609,209

EXAMPLE 4 Adult oriental cockroaches (Blatta orientalis) are placed in 1 liter jars whose inside walls have been wetted with the solutions of the active ingredients. The action is determined after 48 hours.

CyHsO Active ingredient Lowest effective amount in mg of active ingredient per jar A 2.5 l 0.5 2 0.1 3 0.1 4 0.1 5 0.05 6 0.5 7 0.05 8 0.1 9 0.1 10 1.0 H 0.25 12 L0 l3 0.1 14 0.25 15 0.05 17 0.1 19 0.25 20 0.25 24 0.5 25 0.5 26 0.5 27 1.0 28 1.0 29 0.25 21 0.25 3l 0.25 32 0.25

EXAMPLE 5 Action on mosquito larvae (Aedes aegypti) Mosquito larvae in the fourth larval stage are exposed to the action of aqueous emulsions of the active ingredients. The concentration (in ppm) of the active ingredient in water is the amount achieving a larvae kill rate of more than percent.

Concentration of the active ingredient in ppm Active ingredient EXAMPLE 6 1 mm of the acetonic solution of the active ingredients is administered to the ventral abdomen of houseflies (M usca domestica) under CO narcosis.

9 10 The LD may be calculated from the results obwherein R is methyl, ethyl or phenyl, or the radical tamed by using different concentrations of the active ingredients in acetone. The mortality after 4 hours is taken as a basis. &

Active ingredient so A 1.0 'y/fly wherein R" 15 cyclohexyl or phenyl. 2 7m 2. A compound of the formula 3 0.33 'y/ y 4 0.45 7/11}! t H 5 0.4 7 fly NNCH: 6 0.3 -y/fly o,mo s I 7 0.3 ylfly i 0 0 8 0.4 'y/fly N 9 0.3 -ylfly c,H5o ii 10 06 7/ 3 11 045-, y :2 81312 vfgy wherein R is a member selected from the group con- 18 J sisting of methyl, ethyl, propyl, butyl, sec-butyl, tertbutyl and allyl. we claim: 3. A compound of the formula 1. A phosphoric ester of the formula 20 /CH3 o H 0 s NN C R -o s NN-R 1 5- \n L l L Cm /P-0--C\ N C H -o R2-O 2 5 1.

wherein R is a member selected from the group conwhereln sisting of methyl, ethyl, isopropyl and butyl.

R and R each denotes lower alkyl of 1 to 2 carbon 4. The compound of the formula atoms,

R denotes a member selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms,

cyclohexyl, phenyl and phenyl substituted by CEHPO S NliLCH; chloro-, bromo-, methyl-, trifluoromethylor \ll l l O O n1tro-, and N R denotes a member selected from the group con- A,

sisting of alkyl of l to 6 carbon atoms, alkenyl of 3 to 6 carbon atoms, alkoxyalkyl of up to 5 carbon atoms, alkylthioalkyl of up to 6 carbon atoms,

chloroor bromo-subst-ituted alkyl of up to 5 car- The CQmPOUnd of the formula bon atoms, lower alkoxycarbonylmethyl of 1 to 3 carbon atoms in the alkoxy group, cyclohexyl,

on phenyl, phenyl substituted by chloro-, bromo-, 3 methylor trifluoromethyl-, and further members C2H5 0 s I represented by the radical iL i J N C2H5--O it on; HCE J-C 2 3 UNITED STATES PATENT QFFICE CERTIFICATE OF CORRECTION Patent No. 5,7 ,661 Dated February 27, 1973 lnventofls) Wolfram Dietsche et a1 it: is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

rv "i First page, left-hand column, fourth line, Kalmitiveg" should read Kalmitweg eighth line, insert Assignee: Badische Anilin- 8c Soda-Fabrik Aktiengesellschaft, Ludwigshafen/Rhine, Germany eleventh line, insert [30] Foreign Application Priority Data October 1, 1969 Germany P 19 +9 490.7

Column 2, line 9, delete the "N" standing by itself.

Column 4, line in, "P: 11.0)" should read-- P: 11.0 Column 7, line 55, "anphthalenes" should readnaphthalenes Column line-8' 42 to 48.. claim '5 "'C H -O\SI I\T-I\T-CH;=," should read CH -0 S N-- NCH J Ml 0 N N C2H5-O i en -o I R CH it 33 to 37 claim 4 CH should read /CH C2H5-Q 3 N-CH Cal-I5 O S NN-CH l g "CH 1 -0- O CH P-O -=O v CgHs 7-0 l5 c gHs -O R CH Signed and sealed this 12th day of February 1974.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. C Q MARSHALL DANN Attesting Officer ommissioner of Patents 

2. A compound of the formula wherein R3 is a member selected from the group consisting of methyl, ethyl, propyl, butyl, sec-butyl, tert-butyl and allyl.
 3. A compound of the formula wherein R3 is a member selected from the group consisting of methyl, ethyl, isopropyl and butyl.
 4. The compound of the formula
 5. The compound of the formula 